Railway truck with air springs



Aug. 14, 1956 R. LICH 2,753,549

RAILWAY TRUCK WITH AIR SPRINGS Filed Dec. 2, 1954 2 Sheets-Sheet 1INVENTOR. e/c/mea 1. L/CH Aug. 14, 1956 R. L. |c|-| RAILWAY TRUCK WITHAIR SPRINGS 2 Sheets-Sheet 2 Filed Dec. 2, 1954 INVENTOR. E/CHAED L.L/CH United States Patent "2,758,549 RAILWAY TRUCK AIR SPRINGS RichardL.Lich, St. :Louis, Mo., assigu'or to General Steel Ciifinge'Corporatiou,Granit'e'City, 111., a corporation 0 111015 a I Application December 2,1954, Serial No. 472,610 '15 Claims. '(Cl.105-'197)- The inventionrelates to railway rolling stock and more particularly to trucksforlightweight railway cars embody-' ing elastic-walled air springsforyieldingly supporting the truck frame and bolster from the axles andwheels.

In conventional heavyweight railway cars, where the ratio of light toloaded weight is relatively high, metal springs having a constantdeflection rate are fairly satisfactory because there is little changein the natural frequency of spring oscillation between full-loadconditions and no-load conditions. The present trend in railwaypassenger rolling stock is toward lightweight cars. In such cars theratio of light to loaded weight is much lower than in heavy weight cars,with the result that metal springs of the type generally usedinaconventional heavyweight cars do not provide desirable ridingqualities under all load conditions, If such springs are designed toprovide a smooth ride when the car is fully loaded, "they willnotprovide a correspondingly smooth ride Whenthe vehicle is lightly loadedor unloaded, since good riding qualities are largely a function of thenatural frequency of oscillation of the springs, which, in turn, is afunction of deflection rate and load, and varies inversely with respectto the load, all other factors beingequal. For example, if aconstant-deflection spring is designed to provide a desirable naturalfrequency for a loaded car, as the load is decreased or removedentirely, the natural frequencyincreases, with consequent deteriorationin riding characteristics. Uniformly good riding characteristics can beprovided for lightweight cars under all load conditions by using airspring systems, since such systems can be readily designed to provide avariable deflection rate which increases as the load increases,resultingin a substantially constant natural frequency throughout theload range. Furthermore, vin lightweight ears equipped with conventionalmetal springs, variations in loading cause large spring deflections withcorresponding variations in coupler'height. The maintenance of standardcouplerheight is of the utmost importance'in order that cars may becoupled to each other whenever desired, regardless of variations inloading. With air springs, simple mechanisms may be utilized to maintaincoupler height substantially constant under all load conditions.

Air springs of the general type referred to have been suggested for useon railway trucks but in such fashion that the truck does not retainsome desirable features generallypresent in conventional truckstructures, such as stability of the truck bolster, a low center ofgravity of the truck load-supporting member, and accommodation ofrelative movement of the truck load-supporting member and the truckrunning gear transversely of the frame to readily absorb and damplateral forces when the truck passes from straight track to curved trackand vice versa. Accordingly, it is the general object of theinvention toprovide a truck :for lightweight railway cars in which a desirablespring frequency is maintained substantially constant-throughout theload range of the cars, and with which simple means may be utilized. formaintaining 2,758,549 Patented Aug. 14, 1956 coupler'heightsubstantially constant regardless of loading.

A further objectof the invention is to provide .a truck adapted "toaccommodateair-springs and their reservoirs and at the same time providegreater lateral and longitudinal stability than is provided by trucksheretofore adapted for use with air springs.

These and other detail objects of the invention are attained by thestructures illustrated in the accompanying drawings, in which:

Figure l'is a top view of one longitudinal half of a railway four-wheeltruck embodying the invention.

Figure 2 is atop view of the structure shown in Figure .1, the righthand portion of the drawing showing only the truck frame and thelefthand portion showing only the truck equalizers with equalizer springseats.

Figure 3 is in part aside elevation and in part a longitudinal verticalsection taken on the line 33 of Figure 1.

Figure '4 is a vertical transverse section taken on the line 44 ofFigure Figure 5 is a detailed vertical transverse section taken on theline '5-5 of Figure 1.

Figure 6 is a side elevationlargely diagrammatic, of a truck embodyinganother form of the invention, 'a portion of the right hand end of thetruck being sectionalized along the line 6' 6 of Figure 7.

Figure 7 is a transverse vertical section taken on the line 7-7 ofFigure 6.

Figure 8 is a similar side elevation similarly sectionalizedillustrating another form of the invention.

Figure 9 is 'a' similar elevation illustrating another form o'ftheinvention.

The truck shown .in Figures 1-5 includes axles 1, 2 with Wheels 3 and 4,respectively, and journal boxes 5 and 6, respectively. An equalizercomprising spaced bars 7 extends between the wheel axles and is of thetype in which the end'portions of'the bars are elevated and rest uponthe boxes and the intermediate portions of the bars are dropped to alower level and extend to points adjacent the opposing faces offtheWheel treads.

The axles are heldin spaced relation to each other and againstsubstantial relative movement transversely of the truck by a rigid truckframe, preferably of one piece casting, having wheel pieces 8,transverse end members 9, and transverse intermediate transoms 10. TheWheel pieces are provided with depending pedestals 11, 12, slidablyreceiving journal boxes 5, 6 between them.

The truck frame is supported from the equalizers by upright coil springs13, spaced apart lengthwise of the truck and mounted on seats '14adjacent to the ends of the drop portion'o f the equalizer. Projectingoutwardly and downwardly from each Wheel piece 8 is a bracket 15alongated lengthwise of the truck and forming an upwardly facing seatfor an air spring.

The air spring consists'essentially of a pair of elongated chambers 16,17, having elastic walls and separated by an intermediate web 18 andforming a bellows-like structure capable of retaining 'air undercompression and adapted to compress and expand vertically to absorbvertical load and shocks during operation of the vehicle. Preferably anair reservoir 19 is associated With each elastic wall chamber assemblyand mounts'the latter on the truck frame bracket '15. Chambers 16 and 17are interconnected by restricted ports 20 and the chambers are connectedto reservoir 19 by suitable valves well-known in the air spring artwhich maintain air pressure in the overlie and receive the upper portionof air spring chamber 17.

This construction results in. a four wheel equalized truck with thetruck frame supported at widely spaced points lengthwise of the truck tobetter resist galloping, the simultaneous rising of one end and loweringof the other end, and the truck bolster is similarly supported at widelyspaced points lengthwise of the truck, whichincreases its stabilitylengthwise of the truck. The narrow elongated contour of the air springand its mounting outboard of the truck frame and equalizers makespossible the support of the air spring at a low level inasmuch as thereservoir portion of the air spring is at substantially the same levelas theequalizer coil springs.

There is no air spring structure inboard of the wheel pieces andequalizers to interfere with brake rigging and accordingly it is notnecessary to increase the truck wheel base to accommodate the airsprings. The narrow elongated formation of the air spring avoids suchoutward projection of the parts beyond the clearance limit lineindicated at L. Preferably, the truck frame and bolster are held againstmovement longitudinally of the truck by a well-known anchor device 21,adapted to yield transversely of its length to accommodate relativevertical and lateral movements of the bolster and truck frame. The airspring will yield laterally of the truck to accommodate shifting of thebolster when the truck passes between curved and tangent track.

Figures 6 and 7 illustrate, largely diagrammatically, anotherarrangement corresponding generally to that shown in Figures 1-5 butdiffering therefrom in the provision of an air spring structure forsupporting the truck frame on the equalizers 31. In this arrangement,two

air springs 32 and 33 are arranged end to end and lengthwise of theequalizer, each spring including elastic-wall pneumatic chambers similarto chambers 16 and 17, but shorter, and each having associated therewithan air reservoir 34 positioned between equalizer bars 31. This supportof the truck frame does not affect the truck frame brackets 35, or themounting of the air springs 36 thereon, or the support of the truckbolster 37 upon air springs 36.

Figure 8 illustrates another arrangement in which the truck frame 40 issupported from equalizer bars 41 by air springs 42 and the bolster 43 issupported from the truck frame by air springs 44, but the relativelengths of air springs 42 and 44 are the reverse of the arrangementsshown in Figure 6. A single elongated unit 42 is mounted upon theequalizers and a pair of shorter elongated units 44 are mounted upon thetruck frame end to end lengthwise of the truck.

Figure 9 illustrates another arrangement embodying a combination of airsprings and coil springs, as shown generally in Figures 1-5, but theelongated air spring unit is supported on the equalizer bars 51 andupright coil springs 52 spaced apart lengthwise of the truck are seatedupon the bracket 53 projecting from the truck frame 54 and support thebolster 55 outboard of the truck frame wheel pieces and equalizersprings, as in the other arrangcments.

Each of the structures illustrated attain the advantages set forth inthe introductory portion of the specification and it is obvious that thedetails of the arrangements may be varied other than as shown withoutdeparting from the spirit of the invention and the exclusive use ofthose modifications coming within the scope of the claims iscontemplated.

What is claimed is:

1. In a railway truck, wheeled axles, an equalizer extending betweensaid axles and supported therefrom at each side of the truck, yieldingstructure supported by each equalizer, a truck frame mounted on saidyielding structure and including a wheel piece overlying the same andhaving a bracket projecting outwardly therefrom,

yielding structure supported by said bracket outboard of the equalizer,and a load carrying bolster mounted on said latter-mentioned yieldingstructure, at least one of said structures comprising an elastic-wallpneumatic chamber.

2. A railway truck according to claim 1 in which one of the yieldingstructures comprises a plurality of steel springs spaced apartlengthwise of the truck.

3. A railway truck according to claim 1 in which the yielding structuresupported by the equalizer comprises upright coil springs spaced apartlengthwise of the truck and the yielding structure supported by theframe is a pneumatic chamber elongated lengthwise of the truck andcorresponding in length approximately to the distance over the equalizersprings.

4. A railway truck according to claim 1 in which the yielding structuresupported by the equalizer comprises an elastic-wall pneumatic chamberelongated lengthwise of the truck and extending substantially the entiredistance between the adjacent wheels, and the yielding structuresupported by the truck frame consists of a plurality of steel springsspaced apart lengthwise of the truck to bring them adjacent to the endportions of the elongated pneumatic chamber.

5. A railway truck according to claim 1 in which the yielding structuresupported by the equalizer comprises an elastic-wall pneumatic chamberelongated lengthwise of the truck and extending substantially the entiredistance between the adjacent wheels, and the yielding structuresupported by the truck frame consists of a pair of relatively shortsimilar chambers spaced apart lengthwise of the truck adjacent to theend portions of the elongated chamber on the equalizer.

6. In a railway truck, wheeled axles, an equalizer at each side of thetruck extending between said axles and supported therefrom, yieldingstructure supported by each equalizer, a truck frame mounted on saidyielding structure and including wheel pieces overlying the same, eachprovided with a bracket extending outwardly and downwardly below thelevel of the top of the yielding structure supported by thecorresponding equalizer, yielding structure supported by each bracket,and a load-carrying bolster extending over the wheel pieces and mountedon the latter-mentioned yielding structures, at least one of saidyielding structures comprising an elastic-wall pneumatic chamberpositioned outboard of the equalizers and frame Wheel pieces.

7. A railway truck according to claim 6 in which the yielding structuresupported by the equalizer comprises upright coil springs spaced apartlengthwise of the truck, and the bracket and the yielding structurecarried thereby is elongated lengthwise of the truck to an extentcorresponding to the distance across the upright coil springs on theequalizer.

8. A railway truck according to claim 6 in which an air reservoir isassociated with the pneumatic chamber and is seated on the truck framebracket.

9. A railway truck according to claim 1 in which an air reservoir isassociated with the pneumatic chamber and carries the latter on the airspring supporting part.

10. In a railway truck, wheeled axles with journal boxes, an equalizerat each side of the truck extending between said axles and includingrelatively elevated end portions resting on the journal boxes and arelatively low drop portion extending substantially from alongside onewheel tread to alongside the other wheel tread, yielding structuresupported by each equalizer adjacent to the ends of its drop portion, atruck frame supported by said structure over the ends of the equalizerdrop portion, a yielding structure positioned wholly outboard of eachwheel piece supported by the truck frame over the ends of the equalizerdrop portion, and a load-carrying bolster having an end portionextending lengthwise of the truck and supported on said latter-mentionedyielding structure over the ends of said equalizer drop portion, atleast one of said yielding structures comprising an elastic-wallpneumatic chamber.

11. In a railway truck, wheeled axles with journal boxes, an equalizerextending between said axles at each side of the truck and supportedfrom the journal boxes, a rigid truck frame having depending pedestalsslidably receiving all of said journal boxes and having wheel piecesextending between pedestals at the same side of the truck, yieldingstructures supported by each equalizer and supporting the truck frame atpoints near adjacent pedestals, there being a bracket extendingoutwardly from each Wheel piece and elongated lengthwise of the truckfora distance corresponding to the distance between the points ofsupport of said frame, a rigid bolster extending transversely of thetruck over the frame wheel pieces and having a relatively narrowvehicle-supporting central bearing andhaving relatively wide endportions outboard of the wheel pieces and extending lengthwise of'thetruck a distance corresponding to the distance between the points ofsupport of the truck frame, and an elastic-wall pneumatic chamberextending along the underside of each of said bolster end portions andresting upon the corresponding truck frame bracket.

12. In a railway truck, wheeled axles, an equalizer extending betweensaid axles and supported therefrom at each side of the truck, yieldingstructure supported by each equalizer, a truck frame mounted on saidyielding structure and including a wheel piece overlying the same, andprovided with' a bracket extending outwardly and downwardly below thelevel of the top of the yielding structure supported by the equalizer,yielding structure supported by said brackets and comprising anelasticwall pneumatic chamber projecting upwardly above the level of thewheel piece, and a load-carrying bolster extending over the wheel pieceand mounted on the lattermentioned yielding structure.

13. A railway truck according to claim 1 in which one of the yieldingstructures consists of a pair of devices spaced apart lengthwise of theequalizer and the elasticwall pneumatic chamber is elongated lengthwiseof the equalizer bar and extends lengthwise of the equalizer throughoutthe distance between the axes of the spaced yielding structures.

14. A railway truck according to claim 1 in which each equalizercomprises a pair of bars spaced apart transversely of the truck, therebeing an air reservoir for the elastic-wall pneumatic chamber positionedbetween the bars. 7

15. A railway truck according to claim 1 in which each equalizer is ofthe drop type with a lower portion extending substantially from axle toaxle and with upwardly offset end portions overlying the axles, eachequalizer comprising a pair of bars spaced apart transversely of thetruck, the elastic-wall pneumatic chamber extending substantially thefull length of the lower portion of the equalizer, there being an airreservoir for the elastic-wall pneumatic chamber positioned between theequalizer bars.

References Cited in the file of this patent UNITED STATES PATENTS

